Printing cylinders for high-speed printing systems



Jan. 8, 1957' A, HARTLEY 2,776,618

PRINTING CYLINDERS FOR HIGH-SPEED PRINTING SYSTEMS Filed June 11, 1953 2Sheets-Sheet 2 l ra-4 IN VEN TOR. flay/1.0 4. awn. BY

character in position to be printed.

United States Patent PRINTING CYLINDERS FOR HIGH-SPEED PRINTING SYSTEMSRichard A. Hartley, North Hollywood, Calif., assignor, by mesneassignments, to Hughes Aircraft Company, a corporation of DelawareApplication June 11, 1953, Serial No. 360,998

11 Claims. (Cl. 101-93) This invention relates to printing cylinders forhighspeed printing systems and more particularly to continuouslyrotatable printing cylinders for serially operable high-speed printingsystems in which one line of intelligence information is printed on aprinting medium during one revolution of the printing cylinder.

Relatively recent advances in the field of high-speed electronic dataprocessing machines have fostered the need for relatively high-speedoutput devices to convert processed intelligence information in the formof electrical signals to visual indications of the results of the dataprocessing operation. In particular, there has been an ever increasingneed in the art for high-speed printing systems to rapidly convert theelectrical output signals from the data processing machines to a printedrecord.

The prior art printing systems have two modes of operation, namely,parallel, wherein all like characters in the line of intelligenceinformation are printed simultaneously, and serial, wherein eachcharacter in the line of intelligence information is printedsequentially. In both modes of operation the printing is accomplished byselectively energizing a plurality 'of printing transducers to bring anintermittently movable printing medium into engagement with a rotatableprinting cylinder having a plurality of longitudinally aligned rows oftype characters about its periphery.

In the parallel printing systems of the prior art, the electricalsignals corresponding to all of the characters in the line ofintelligence information are read simultaneously and compared with asignal representing the type The information signals corresponding tothe type character signal are then utilized to actuate their associatedprinting transducers in parallel. In this manner, the complete line ofintelligence information is compared with type character signalscorresponding to all of the characters which may be printed during onerevolution of the printing cylinder and, therefore, the complete line ofintelligence information is printed during one revolution of theprinting cylinder. Although this type of prior art printing systemoperates at relatively high speed, the electrical circuits required toprovide parallel operation are both relatively expensive and complex, Inaddition, the duplication of electrical circuits required to effectparallel operation inherently limits the reliability of this prior artsystem.

In the serially operable printing systems of the prior art theelectrical signals corresponding to the signals in the line ofintelligence information are serially read and sequentially comparedwith a signal representing the type character in position to be printed.The information signals corresponding to the type character signal arethen utilized to serially actuate the associated printing transducers,while the printing cylinder is held stationary. In this manner, all likecharacters corresponding to the printing cylinder position aresequentially printed on the printing medium, after which the printingcylinder is intermittently rotated to each of the succeeding type char-"ice 6 line of intelligence information during one revolution ofinformation is sequentially compared with the type charthe printingcylinder, it is inherently limited in its speed of operation by the factthat the printing cylinder must be intermittently rotated through eachrevolution in order to position each row of type characters beneath theprinting transducers While the complete line of intelligence actersignal. In addition, the printing medium must also be intermittentlyadvanced one line at a time at the end of each printing operation, sincethe printing medium must also be held stationary during the printing ofeach line.

In still another serially operable printing system of the prior art, acontinuously rotatable printing cylinder is utilized for printing a lineof intelligence information on an intermittently movable printingmedium. According to this prior art printing system, however, only onecharacter in the line of intelligence information may be printed duringeach revolution of the printing cylinder. This prior art printingsystem, therefore, has the obvious disadvantage of being a relativelyslow-speed device, since it requires as many revolutions of itsassociated printing cylinder as there are characters in the line ofintelligence information to be printed.

The present invention, on the other hand, obviates the above and otherdisadvantages of the prior art printing systems by providing askewed-type printing cylinder which enables a serially operable printingsystem to print on a continuously movable or intermittently movableprinting medium a full line of intelligence information during onerevolution of the printing cylinder. According to the basic feature ofthe present invention, each row of type characters on the printingcylinder is skewed so that the last character in each row is insubstantially longitudinal alignment with the first character in thenext succeeding row of type characters. Thus, any given type characterrow is sequentially passed beneath all of the associated printingtransducers as the printing cylinder is continuously rotated and, as aresult, each type character in each row of type characters has its owndiscrete and printing position relative to the rotation of the printingcylinder. Accordingly, an entire line of serially presented intelligenceinformation may be printed during one revolution of the skewed-typeprinting cylinder of this invention, by sequentially comparing theelectrical signals corresponding to the characters in the line ofintelligence information with an electrical signal corresponding to therow of type characters which is simulta neously being passedsequentially beneath the associated printing transducers.

According to one embodiment of the present invention, a skewed-typeprinting cylinder is provided in which the type characters in each rowof type characters are immediately adjacent the type characters in thesucceeding row of type characters, thereby most efficiently utilizingthe available area of the printing cylinder periphery. In thisembodiment of the present invention, the printing medium is advancedintermittently after each line of intelligence information has beenprinted.

According to another embodiment of the present invention, a skewed-typeprinting cylinder is provided which may be utilized to print on acontinuously movable printing medium one line of intelligenceinformation during one revolution of the printing cylinder. In thisembodiment of the invention, the characters in each row of typecharacters are spaced from the characters in the succeeding row of typecharacters by a distance equal to or slightly greater than the height ofa type character.

In addition, the present invention provides modified forms of each ofthe above embodiments of the present invention, wherein a predeterminedportion of the printing cylinder periphery is left vacant. In thismanner a time interval is provided during each revolution of theprinting cylinder for entering in associated. electrical circuitsadditional lines of intelligence information to be printed, therebyenabling the serially operable printing system to print one completeline of intelligence information during each revolution of theskewed-type printing cylinder of this invention.

It is, therefore, an object of this invention to provide continuouslyrotatable printing cylinders for serially operable high-speed printingsystems.

It is another object of this invention to provide continuously rotatableprinting cylinders for printing one line of intelligence informationduring one revolution of the printing cylinder in serially operablehigh-speed'printing systems.

An additional object of this invention is to provide continuouslyrotatable skewed-type printing cylinders for serially printing a fullline of intelligence information during one revolution of the printingcylinder.

It is also an object of this invention to provide continuously rotatableskewed-type printing cylinders operable in conjunction with a pluralityof associated printing transducers to sequentially print all of thecharacters in a line of intelligence information during one revolu tionof the printing cylinder.

It is a further object of this invention to provide a continuouslyrotatable skewed-type printing cylinder for use in a serially operableprinting system to print on an intermittently movable printing medium aline of intelligence information for each revolution of the printingcylinder.

Still another object of this invention is to provide a continuouslyrotatable skewed-type printing cylinder which may be utilized in aserially operable printing system to print on a continuously movingprinting me dium a line of intelligence information for each revolutionof the printing cylinder.

It is still another object of this invention to provide skewed-typeprinting cylinders for serially operable printing systems, the rows oftype characters on the printing cylinders being skewed relative to theaxis of rotation of the cylinder so that the last type character in-eachrow of type characters is in substantial longitudinal alignment with thefirst type character in the succeeding row.

Still another object of this invention is to provide printing cylindersfor serially operable printing systems in which the printing cylindersinclude a plurality of skewed rows of type characters disposed about aportion of the periphery of the type cylinder in order to print one lineof intelligence information during each revolution of the printingcylinder.

The novel features which are believed to be characteristic of theinvention, both as to its organization and method of operation, togetherwith further objects and advantages thereof, will be better understoodfrom the following description considered in connection with theaccompanying drawings in which several embodiments of the invention areillustrated by way of examples. It is to be expressly understood,however, that the drawings are for the purpose of illustration anddescription only, and are not intended as a definition of the limits ofthe invention.

Fig. 1 is a schematic diagram of a serially operable printing systemwhich includes one embodiment of a skewed-type printing cylinder,according to the present invention;

Fig. 2 is a diagram illustrating the operational printing sequence ofthe printing system shown in Fig. 1;

Fig. 3 is a cross-sectional view of a modified form of the printingcylinder shown in Fig. 1;

Fig. 4 is an isometric view of another embodiment of 4% a skewed-typeprinting cylinder, according to the present invention;

Figs. 4a, 4b and 4c are cross-sectional views of the skewed-typeprinting cylinder shown in Fig. 4 illustrating its mode of operation;and

Fig. 5 is an end view of a modified form of the skewedtype printingcylinder shown in Fig. 4.

Referring now to the drawings, there is shown in Fig. 1 a seriallyoperable high-speed printing system which utilizes one form ofskewed-type printing cylinder according to the present invention forserially printing intelligence information a line at a time. Thehigh-speed printing system includes three basic components, namely, anelectronic data handling system for serially presenting electricaloutput signals corresponding to the intelligence information which is tobe printed, a continuously rotatable sllewed-type printing cylinder andits associated drive mechanism 102, and a printing transducer network,generally designated 104, selectively operable in response to the outputsignals from the data handling system and in cooperation with printingcylinder 100, to serially print on a printing medium 106 theintelligence information corresponding to the output signals.

In order to most clearly describe the operation of the printing systemand the skewed-type printing cylinders of this invention, it will beassumed that the printing system of Fig. l is capable of printing onprinting medium 106 any one of ten type characters, such as thedecimal'digits' Zero to nine, for example, in each space or column of aten space line. Thus, as shown in Fig. l, transducer network 104includes ten printing transducers, 110 to 119, corresponding,respectively, to the ten spaces or columns in the line. In addition, itwill first be as sumed for purposes of illustration that printing medium106 is moved intermittently relative to the printing transducers, or inother words, that the printing medium remains stationary while one lineof intelligence information is printed, and is then advanced one lineprior to the printing of the succeeding line.

The electronic data handling system which is utilized to selectivelyoperate the printing transducers is preferably similar to that shown inthe copending application for patent of Eldred Nelson, entitledHigh-Speed Printing System, Serial Number 379,045, filed September 8,1953, which discloses a data handling system and associated printer forserially printing stored intelligence information coded in the binarysystem of numbers.

More particularly, as shown in Fig. l, the intelligence information tobe printed is stored in a data storage unit which includes a memory unit122 for storing electrical signals corresponding to the successivecharacters of one line of intelligence information. Memory unit 122,which may. be a magnetic drum, for example, is operable in cooperationwith a shifting register 3.24 to function as a circulating register inorder to serially present at the output circuit of shifting register 124elec trical signals corresponding to the successive characters of thestored line of intelligence information. in addition, memory unit 120 issynchronized with drive mechanism 102 in order to circulate theintelligence information through shifting register 124 once for eachcharacter represented on type cylinder 100, thereby assuring that thefull line of information is scanned once for each character which may beprinted during one revolution of type cylinder 100.

Data storage unit 120 also includes a clock pulse generator 126 operableunder the control of memory unit 122 to apply a periodically recurringclock pulse signal to a column counter 128 which controls theoperational sequence of printing transducers 11G to 119 by sequentiallyopeningeach of ten respectively associated and gates 130through 139 inaccordance with the spacing in the line of intelligence information ofthe character represented by the output signal from register 124.

In order to selectively energize transducers 104 to print the propertype characters on medium 106, the data handling system also iicludescomponent circuits for indicating the rotational position of typecylinder 100 relative to the printing transducers. Accordingly, the datahandling system includes a character counter 140 which is electricallyindexed according to the position of type cylinder 100 by an associatedpulse generator 142 which, in turn, is operated under the control oftypecylinder drive mechanism 102. Character counter 140 thus presents anelectrical output signal corresponding to the character on printingcylinder ltltl which is in position to be printed.

The output signal from character counter 140 is applied to a comparatorcircuit 144 which functions to compare the output signals from shiftingregister 124 and character counter 140 in order to present an electricaloutput signal to energize a preselected one of printing transducers 110to 119 whenever the signals presented by shifting register 124 andcounter 140 correspond to the same information character.

The specific printing transducer which is energized to print is, ofcourse, determined by which of the associated gates has been opened bycolumn counter 128. For example, if comparator 144 produces an outputsignal when the signal presented at the output circuit of shiftingregister 124 corresponds to the character in the fourth space of thestored line of intelligence information, gate 133 will be opened bycolumn counter 128 and transducer 113 will therefore be energized toprint the desired character in the fourth space or column on printing medium 106.

Printing transducers 110 to 119 are preferably similar to the printingtransducers shownin the co-pending application for patent of Baldwin etal., entitled Electromechanical Transducer, Serial Number 377,956, filedSeptember 1, 1953, now abandoned, or the co-pending application forpatent of Fomenko et al., entitled High- Speed Printing Transducer,"Serial Number 377,818, filed September 1, 1953. As shown in Fig. 1, eachprinting transducer includes a hammer, such as hammer 146 of transducer110, which is adapted to move toward skewedtype printing cylinder 100upon energization of its associated transducer, thereby printing onmedium 106 the type character on type cylinder 100 which is beneath thehammer when the transducer is energized.

The skewed-type printing cylinder, according to the present invention,includes a series or plurality of skewed rows of raised type characters,one row being provided for each different type character which may beprinted. The number of type characters provided in each row correspondsto the number of columns or spaces which may be printed in one line. Inaddition, each character is skewed with respect to the other charactersin the same row so that the last character in each row is in substantiallongitudinal alignment with the first character in the next succeedingrow The circumferential displacement through which each type characteris skewed with respect to adjacent type characters in the same row isidentical to the circumferential displacement the last type character ineach row is skewed with respect to the first type character in the nextsucceeding row, this distance being determined for printing cylinder 100by the following equation:

d=circumfereutial displacement per character:

where:

According to the present invention, therefore, type in Fig. 1.

cylinder includes ten skewed rows of type characters for presenting thetype characters zero to nine, respectively. In addition, each row oftype characters includes ten identical type characters corresponding tothe ten columns or spaces in the line of intelligence information to beprinted on medium 106, each character being circumferentially displacedwith respect to adjacent characters by the distance Stated difierently,the circumferential displacement from the bottom of one type characterin any row to the bottom of the adjacent type character in the row isequal to In a similar manner, the circumferential displacement betweenthe bottom of the last type character in any row and the bottom of thefirst type character in the succeeding row is equal to The direction ofskew of the rows of type characters is determined by the direction ofrotation of the printing cylinder and by the sequence in whichrtheassociated printing transducers would be energized if the line to beprinted contained the same character in each line space. Thus, in Fig.1, for example, if it is assumed that printingcylinder 100 is to berotated at constant speed in the direction of arrow 148 and thattransducers 100 to 119 are sequentially energizable from left to right,the direction of skew is upward from left to right as viewed inoperation, the time interval required for printing cylinder 1th) totraverse the skewing distance or circumferential displacement percharacter is substantially identical to the time interval required forthe circulating register to shift into shifting register 124 the nextsucceeding character in the stored line of intelligence information.

Referring now to Fig. 2, there is shown a diagram correlating theprinting spaces zero to nine with the type characters which are inprinting position in order to illustrate the sequence in which a typicalline of intelligence information may be printed. It will be assumed thatthe line of intelligence information to be printed includes thesequential characters, 0340549236 and that the first zero in the zerosrow on skewed-type printing cylinder 100 is immediately beneath hammer146 of transducer when the first character of the line of intelligenceinformation is shifted into shifting register 124. Accordingly,comparator circuit 144 will now produce an output signal,

since the signals applied to the comparator circuit from charactercounter 140 and shifting register 124 both correspond to the characterzero. If it is also assumed that column counter 128 is indexed from datastorage unit to open gate 130, the output signal from comparator circuit144 will energize transducer 110 to print in the zero space or column onmedium 106 the decimal character zero.

As the second and third characters in the line of intelligenceinformation are sequentially shifted through shifting register 124,skewed-type printing cylinder 100 continues to rotate so that firsttransducer 111 and then transducer 112 are in position for printing thecharacter zero. However, comparator circuit 144 produces no outputsignal for operating these transducers at this time, because the outputsignal from character counter corresponds to the decimal character zerowhereas the characters represented by the output signals from shiftingregister 124 correspond to the sequential information characters threeand four.

When electrical signals corresponding to the character zero in thefourth space in the line of intelligence information are shifted intoshifting register 124, gate 133 is opened by column counter 128 andtransducer 113 is in position, relative to skewed-type printing cylinder100, for printing the character zero. Accordingly, comparator circuit144 produces'an output signal to energize transducer 113 to print in thefourth column or space of medium 106 the character zero, as shown inFig. 2.

As the remainder of the line of intelligence information is circulatedthrough shifting register 124, gates 134 through 139 are sequentiallyopened for printing the character zero. However, none of the associatedtransducers are energized because the character zero is not representedin the fourth to ninth spaces of the line of intelligence informationbeing printed.

When the line of intelligence information is recirculated to againsequentially shift through shifting register 124, skewed-type printingcylinder 18% is in posi tion relative to the printing transducers tosequentially pass the type character one beneath each of transducers1-10 to 119 and, simultaneously, to present an electrical signalcorresponding to the character one at the output circuit of charactercounter 149. It is clear, however, that no transducer will be energizedduring this interval, since the character one is not included in thestored line of intelligence information.

Consider now the operation of the printing system as the storedinformation is serially shifted through shifting register 124 for thethird time. The type character two is now sequentially positionedbeneath each of trans ducers 110 to 119 by the rotation of type cylinder100 and the output signal from character counter 140 corresponds to thecharacter two. Accordingly, when the character two in the eighth spaceof the stored line of intelligence information is shifted into shiftingregister 124, comparator 14-1- produces an output signal which is passedby gate 137, thereby energizing transducer 117 to print in the eighthspace on printing medium 106 the character two, as illustrated in Fig.2.

In a similar manner it may be shown that when the stored line ofintelligence information is circulated through shifting register 124 forthe fourth time, the character three will be printed first in the secondline space and then in the ninth line space on printing medium 106.Thus, as shown in Fig. 2, each of the characters in the line ofintelligence information will be printed in its proper space on printingmedium 106 when comparator circuit 144 senses equality between thecharacter to be printed, as represented by the output signal fromshifting register 124, and the type characters in printing position, asrepresented by the output signal from character counter 140.

It is apparent, therefore, that the complete line of intelligenceinformation will be printed on one line of medium 106 during onerevolution of the skewed-type printing cylinder of this invention.

advance medium 106 into position for printing the next succeeding line.In addition, a succeeding line of intelligence information issimultaneously entered into data storage unit 120 through associatedcircuits, not shown, in order to prepare the electronic data handlingsystem for presenting the succeeding line of intelligence information tobe printed.

During the interval when printing medium 1&6 is being advanced andadditional intelligence information is being entered in data storageunit 120, printing cylinder 100 continues to rotate. Accordingly, whenthe printing system is ready to print the next succeeding line ofintelligence information, printing cylinder lfltlmay be in a positionrelative to the printing transducers which is different from thestarting position assumed for printing the preceding line ofintelligence information. In practice, either of two methods may beutilized to coordinate the printing system to start the printing. of thenext succeeding line- Firstly, printing cylinder 100 may be permitted toro- Upon completion of the printing operation, drive mechanism 102operates to tate through one complete revolution during which noprinting is done in order to provide a time interval for advancingprinting medium 106 and for entering additional intelligence informationin the data storage unit. if this technique is utilized, the printingsystem effectively averages two revolutions of the printing cylinder foreach line which is printed, although the actual printing is done duringonly one revolution of the printing cylinder.

The second method which may be utilized is to start printing thesucceeding line of intelligence information whenever the printing mediumand the data handling system are prepared for printing the succeedingline. Thus, if after the end of the first printing cycle, type cylinderhas rotated relative to the transducers so that type character two is inposition for printing, the printing system may start the printingoperation by first scanning the line of intelligence information for thecharacter two.

The advantage of utilizing this method is that the printing of each linerequires only one and some fraction of a revolution of the printingcylinder to print a single line, thereby providing faster operation.However, if this method is utilized, an additional circuit must beprovided to insure that printing cylinder 100 is rotated through atleast one complete revolution after each printing operation is started,in order to be certain that the line of intelligence information isscanned once for each character which might be printed.

Referring now to Fig. 3, there is shown a cross-sectional view of amodified skewed-type printing cylinder 360 which may be utilized toprint one line of intelligence information for each revolution of thetype cylinder notwithstanding the fact that a finite time interval isrequired to intermittently advance the printing medium and to enteradditional intelligence information in the data storage unit. As shownin Fig. 3, printing cylinder 300, according to the present invention,includes a plurality of skewed rows of type characters, such ascharacters zero to nine, for example, which are disposed about only aportion of the periphery of the printing cylinder with a vacant spaceexisting between the first and last rows of type characters.

In order to determine the proportion of the printing cylinder peripherywhich should be left vacant, it is preferable first to determine thenumber of lines of intelligence information which could be printedduring the time required to intermittently advance the printing mediumand to enter an additional line of intelligence information in the datastorage unit. The periphery of the type cylinder is then divided into anintegral number of segments, the number of segments being equal to thenumber of type characters which may be printed during one revolutionplus the number of lines which could be printed during the advance ofthe printing medium. Accordingly, if the type characters which may beprinted are located in adjacent segments on the printing cylinderperiphery, it is clear that at least one segment of the cylinderperiphery will be left vacant between the first and last rows of typecharacters on the printing cylinder in order to provide a time intervalduring each revolution of the printing cylinder for advancing theprinting medium. As shown in Fig. 3, for example, cylinder 300 includestwo vacant segments 302 and 304 between type character nine and typecharacter zero.

Consider now the operation of the printing system shown in Fig. 1 if askewed-type printing cylinder having a cross-sectional configurationsuch as that shown in Fig. 3 is utilized therewitl. Obviously, a fullline of intelligence information may now be printed, in the mannerpreviously described with reference to Fig. 2, during only of arevolution of printing cylinder 3049. Accordingiy, the printing mediummay be advanced and additional information may be entered into the datastorage unit while the printing cylinder is completing its revolutionand while blank segments 302 and 304 are passing beneath the-printingtransducers. Thus, the. printing system is now capable of printing onefull line of intelligence information for each revolution of the skewedtype printing cylinder of this invention.

It will be recognized by those skilled in the art that the vacant spaceprovided between the first and last rows of type characters on printingcylinder 300 does not necessarily bear any special relationship with theportion of the printing cylinder periphery upon which the rows of typecharacters are distributed. Thus the following generic equation may beutilized to determine the circumferential displacement (d) of each typecharacter relative to adjacent type characters in each of the severalembodiments of the present invention:

r=the radius ofthe printing cylinder;

n=the number of rows of type characters;

m=number of characters in each row; and

s=a number, preferably an integer, which is not less than the value ofn. 1

In the foregoing description of the skewed-type printing cylinders ofthis invention, it has been assumed that the printing. medium remainsstationary while each line of intelligence information is printed, andis moved intermittently between successive printing operations. It willbe apparent from the description below, however, that the skewed-typeprinting cylinders of the present invention may also be utilized toserially print a line of intelligence information on a printing mediumwhich moves continuously relative to the printing transducers.

Referring now to Fig. 4, there is shown a skewed-type printing cylinder400, according to the present invention, which may be employed with thedata handling system and transducers shown in Fig. 1 for printing on acontinuously movable printing medium. Printing cylinder 400 is similarto the previously described skewed-type printing cylinder 100 of Fig. lwith regard to the number of skewed rows of type characters and themanner in which each individual character is circurnferentiallydisplaced with respect to adjacent characters.

The principal difierence between these printing cylinders is that thetype characters in each row of type characters on printing cylinder 400are separated or spaced from the type characters in the adjacent rows bya distance equal to at least the height of one type character. Thus, asshown in Fig. 4, for example, the distance 4'02 between type characterszero and one is equal to or larger than the height of any one typecharacter, as designated by the distance 404. In addition, it will benoted that the direction in which the rows of type characters are skewedon printing cylinder 400 has been reversed in order to illustrate howthe type characters may be skewed when the printing cylinder is rotatedin the direction of arrow 406.

Referring now to Figs. 4a, 4b and 4c, there are shown threecross-sectional views of printing cylinder 400, taken through the firstcolumn of type characters, which illustrate the cooperation of theprinting cylinder and a printing transducer hammer 410 in printingeither the characters zero, five or nine, respectively, in a given lineon a printing medium 412. Printing medium 412 is positioned betweenhammer 410 and printing cylinder 400 and is continuously moved in thedirection of arrow 413 at the rate of one line per revolution of theprinting cylinder. The movement of the printing medium relative tohammer 410 during one revolution of the printing cylinder is illustratedin Figs. 4a, 4b and 40 by the respective positions of a reference point414 on the printing medium.

In order to provide uniformly aligned printed characters on printingmedium 412 when a line of intelligence information is printed thereon,the printing positions of the different type characters relative tohammer 410must be sequentially varied in accordance with the movement ofthe printing medium relative to the printing hammer. One manner in whichthis may be accomplished is by varying the time at which the printingtransducer is energizable to print succeeding characters. For example,if hammer 410 is movable to print only when its center line 416 isaligned with one of the ten timing marks to to 19, corresponding to theten rows of type characters, respectively, it may be seen that each typecharacter has a different printing position relative to the printingsurface of the hammer. .In addition, the width of hammer 416 is madeequal to the distance separating the start one type character from thestart of the next type character. In other words, the width of eachprinting hammer is equal to the sum of distances 402 and 404, as shownin Fig. 4, in order to provide suflicient hammer printing surface tocooperate fully with any type character which may be printed.

Consider now the operation of skewed-type printing cylinder 400 when itis desired to print the character zero on printing medium 412 in a linecentered about reference point 414. Referring now to Fig. 4a, assume.that the instant when reference point 414 is directly over typecharacter zero, timing mark to is aligned with center line 416 of hammer410. Accordingly, hammer 4111 is actuated to print the character zeroutilizing only the right hand portion of the hammer, as viewed in Fig.4a.

Assume now that it is desired to print instead the character five in aline centered about reference point 414. v With reference to Fig. 4b, itmay be seen that printing medium 412 and its reference point 414 hasmoved approximately one half of a line length from its initial positionduring the interval required to rotate printing cylinder 400 to theposition for printing character five. Accordingly, hammer 410 isactuated to print the character five when the character is substantiallycentered with respect to the hammer, or, in other words, when timingmark is is aligned with center line 416 of the printing hammer. In asimilar manner, it may be seen from Fig. 40 that the left-hand portionof hammer 410 would be utilized in order to print the character nine ona line centered about reference point 414.

It will be recognized, of course, that if skewed-type cylinder 400 isutilized in the printing system shown in Fig. 1, each line ofintelligence information should be shifted into register 124 andcirculated in accordance with the timing marks to to its as shown inFigs. 4a

through 40. In addition, it will be recognized that in order to utilizeprinting cylinder 400 in the printing system of Fig. 1, no printing maybe performed during a portion or all of every other revolution of theprinting cylinder, since additional intelligence informationcorresponding to the next successive line to be printed must be enteredin data storage unit 120.

Assume now that it is desired to print one line of intelligenceinformation on a continuously moving printing medium during eachrevolution of the printing cylinder. This may be accomplished byutilizing a skewedtype printing cylinder, according to the presentinvention, in which the spacing between adjacent skewed rows of typecharacters is similar to that shown in Fig. 4, but in which a largerspacing is utilized between the first and last characters which may beprinted, as previously described with regard to Fig. 3.

Referring now to Fig. 5, there is shown an end view of a skewed-typeprinting cylinder 500, according to the present invention, whichincludes two blank or vacant spaces 502 and 504 between the typecharacter zero and the type character nine. When printing cylinder 500is utilized in the printing system of Fig. 1, several distinctadvantages may be realized.

Firstly, the complete vacant space between type character rows zero andnine will provide additional separation between the printed charactersin two successive lines of intelligence information printed on theprinting medium. Secondly, the spacing designated 502 provides a timeinterval during each revolution of the printing cylinder when noprinting is done, thereby permitting the entry of additionalintelligence information in the associated data handling system. It willbe recognized that the time interval during each revolution whichcorresponds to the spacing designated 504 is that interval in which theline of intelligence information is serially compared in the associatedcomparator circuit for printing the character nine.

A skewed-type printing cylinder of the general configuration shown inFig. 5 may also be provided in which the type characters subtend an evensmaller portion of the printing cylinder periphery in the manner shownin Fig. 3, thereby providing even larger spacing on the printing mediumbetween successive lines of printed intelligence information. Moreover,it will be recognized that additional spacing between the first and lasttype characters on the printing cylinder will provide additional time inwhich to enter new intelligence information into the data storage unit,after one line is printed, but before the printing cylinder hascompleted one revolution and is in position relative to the transducersfor printing the succeeding line of intelligence information. Inpractice, the arc subtended by the type characters on the printingcylinder periphery may often be of the order of 240 or less.

It should be pointed out that each of the basic skewedtype printingcylinders shown in Figs. 1 and 4 has certain relative advantages overthe other. For example, printing cylinder 400 in Fig. 4, as previouslypointed out, may be utilized to print on a continuously moving printingmedium, whereas the use of printing cylinder 100 in Fig. 1 requires thatthe printing medium be intermittently advanced one line at a time,thereby requiring slightly more complicated mechanical structure indrive mechanism 102. On the other hand, printing cylinder 100 mostefficiently utilizes the available surface of the printing cylinder byvirtue of the fact that adjacent rows of type characters are closelypacked, whereas the adjacent rows of type characters on printingcylinder 4% are spaced from each other by the height of a typecharacter. Stated differently, for a given printing cylinder peripheryand a given number of different type characters which may be printed,printing cylinder 100 permits the use of type characters ofsubstantially twice the size of the corresponding type characters onprinting cylinder 4-00. In addition, it should be clear that theindividual type characters may be engraved on the skewed-type printingcylinders of the present invention, if it is desired to print on thesurface of the printing medium facing the printing cylinder.

Summarizing the invention, the skewed-type printing cylinders of thepresent invention provide continuously rotatable printing cylinderswhich may be utilized with a serially operable printing system to printon a continuously movable or intermittently movable printing medium afull line of intelligence information during one revolution of theprinting cylinder.

What is claimed as new is:

l. A continuously rotatable printing cylinder assembly for a seriallyoperable printing system, said assembly comprising: a plurality ofsequentially energizable printing transducers, disposed along a straightline, for printing intelligence information, a cylindrical member havingan axis and being rotatable about said axis, said axis beingsubstantially parallel to a reference line taken through a correspondingpoint on each of the plurality of transducers; and a series of rows oftype characters longitudinally disposed about at least aportion of theperiphery of said cylindrical member, each of said rows beingidentically skewed with respect to said axis of said cylindrical memberand with respect to each other, each row corresponding to a differenttype character and the characters in each row being identical andcorresponding in number to the number of transducers, the distancebetween adjacent rows being constant, the last type character in atleast one of said rows being in substantially longitudinal alignmentwith the first type character in the succeeding row.

2. The printing cylinder defined in claim 1 wherein said series of rowsof type characters are uniformly distributed about the periphery of saidcylindrical member.

3. The printing cylinder defined in claim 1 wherein each of said rows oftype characters is separated from the adjacent rows by a distance equalto at least the height of one type character.

4. The printing cylinder defined in claim 3 wherein said series of rowsof type characters are disposed about the entire periphery of saidcylindrical member.

5. A continuously rotatable printing cylinder assembly for a seriallyoperable printing system, said assembly comprising: a plurality ofelectrically controllable printing transducers, disposed along asubstantially straight line, for printing intelligence information; arotatable cylindrical printing member; and at least first and secondrows of type characters disposed about a portion of the cylindricalsurface of said printing member, said first row of type charactersincluding a plurality of like type characters corresponding in number tothe number of printing transducers, said second row including acorresponding plurality of like type characters different from thecharacters in said first row, correspondingly positioned type charactersin said respective rows being selectively operably disposed with respectto a correspondingly disposed transducer in said line of transducers,each of said rows of type characters being skewed relative to the axisof rotation of said printing member, each of said type characters ineach of said rows being circumferentially displaced from the adjacenttype characters in the same row by a distance (d) defined by theequation,

2m" where: r=radius of said cylindrical printing member; m=number oftype characters in each of said first and second rows of typecharacters; and s=a number not less than the number of rows of typecharacters on said printing member.

6. The printing cylinder defined in claim 5 wherein the last typecharacter in one of said first and second rows is circumferentiallydisplaced from the first type character in the other of said rows by thedistance (d).

7. The printing cylinder defined in claim 5 wherein s is an integergreater than the number of rows of type characters and wherein saidfirst and second rows of type characters are disposed immediatelyadjacent each other.

8. A continuously rotatable printing cylinder assembly for a seriallyoperable printing system, said assembly comprising: a cylindricalprinting member having a longitudinal axis and being rotatablethereabout, the periphery of said member being divided into first andsecond longitudinal portions; a series of substantially longitudinallydisposed rows of type characters distributed uniformly about said firstportion of the periphery of said cylindrical member, each of said rowsbeing identically skewed with respect to said axis, a plurality ofadjacent and sequentially energizable printing transducers, respectivelyoperatively disposed with respect to said type characters and operablein conjunction with said cylindrical printing member for printingintelligence information, the number of type characters in each of saidrows corresponding to the number of printing transducers, each rowcorresponding to a different character and the characters of each rowbeing identical; the circumferential spacing between adjacent charactersin each row being equal to the circumferential spacing between the lastcharacter in one row and the first character in the succeeding rowwhereby intelligence information may be sequentially printed when saidfirst portion of said member is adjacent said transducers and the recordmedium may be advanced when said second portion of said member isadjacent said transducers.

9. In a high-speed printing system for serially printing a plurality ofcharacters, represented by a corresponding plurality of appliedelectrical signals, respectively, in a line upon a printing medium, thecombination comprising: a plurality of printing transducerscorresponding to the number of characters in the line to be printed,said transducers being positioned adjacent one surface of the printingmedium in a plane extending through the medium along the line; and aprinting cylinder rotatable about an axis in the plane of saidtransducers, said cylinder being positioned adjacent the other surfaceof the printing medium and having a series of identically skewed rows oftype characters longitudinally disposed about at least a portion of itsperiphery, each or said rows corresponding to a dilferent character tobe printed and including a plurality of identical type characterscorresponding to said plurality of transducers respectively, the lasttype character of at least one of said rows being in substantiallylongitudinal alignment with the first type character of the succeedingrow.

10. In a high-speed printing system for serially printing a plurality ofcharacters, represented by a corresponding plurality of appliedelectrical signals, respectively, in a line upon a printing medium, thecombination comprising: a plurality of printing transducerscorresponding to the number of characters in the line to be printed,said transducers being positioned adjacent one surface of the printingmedium in a plane extending through the medium along the line; aprinting cylinder having an axis in the plane of said transducers andbeing rotatable about said axis, said cylinder being positioned adjacentto the other surface of the printing medium and having a series ofidentically skewed rows of type characters longitudinally disposed aboutat least a portion of its periphery, each of said rows corresponding toa diflerent character to be printed and including a plurality ofidentical type characters corresponding to said plurality of transducersrespectively, the last type character of at least one of said rows beingin substantially longitudinal alignment with the first type character ofthe succeeding row; means for continuously rotating said printingcylinder to sequentially pass each of said skewed rows of typecharacters beneath said printing transducers; and electrical meansresponsive to the applied electrical signals and to the position of saidtype cylinder relative to said transducers for selectively energizingsaid transducers when the characters represented by the appliedelectrical signals correspond to the type character being passed beneathsaid transducers.

11. In a serially operable high-speed printing system for printing aplurality of characters in a line of intelligence informationrepresented by a corresponding plurality of applied electrical signals,respectively, in a line upon a printing medium, the combinationcomprising: a plurality of printing transducers corresponding to thesequential characters in the line of intelligence information to beprinted, said transducers being positioned adjacent one surface of theprinting medium in a plane extending through the medium along the line;a printing cylinder rotatable about an axis in the plane of saidtransducers, said cylinder being positioned adjacent the other surfaceof the printing medium and having a series of identically skewed rows oftype characters longitudinally disposed about at least a portion of theperiphery thereof, each of said rows corresponding to a differentcharacter to be printed and including a plurality of identical typecharacters corresponding to said plurality of transducers, respectively,the last type character of at least one of said rows beingcircumferentially displaced from the first type character of thesucceeding row by a distance equal to the circumferential displacementbetween adjacent type characters in each of said skewedrows; means forrotating said printing cylinder at a constant speed to sequentially passeach row of type characters beneath said transducers; and electricalmeans responsive to the applied electrical signals and to the positionof said printing cylinder relative to said transducers for selectivelyenergizing each transducer when the character represented by thecorresponding applied electrical signal corresponds to the typecharacter passing beneath said transducer,

References Cited in the file of this patent UNITED STATES PATENTS734,526 Ennis July 28, 1903 1,405,722 Siepman Feb. 7, 1922 1,530,871Welter Mar. 24, 1925 1,753,961 Zworykin Apr. 8, 1930 1,781,793 SpencerNov. 18, 1930 1,944,692 Maby Ian. 23, 1934 2,029,220 Brawn Jan. 28, 19362,053,063 Bryce Sept. 1, 1936 2,540,654 Cohen Feb. 6, 1951

